399

NSave Nature to Survive

6(3) : 399-402, 2011 www.thebioscan.in

ANATOMY AND HISTOLOGY OF THE ALIMENTARY CANAL OF

ADULT PAPILIO POLYTES POLYTES L. (LEPIDOPTERA:

PAPILIONIDAE)

S. M. GAIKWAD*, S. R. ALAND, A. B. MAMLAYYA AND G. P. BHAWANE

Department of Zoology, Shivaji University, Kolhapur - 416 004

E-mail: gaikwadsm@rediffmail.com

INTRODUCTION

The alimentary canal is concerned with the digestion of

consumed food and absorption of it. Since the time of Pyle

(1940), the study of the digestive system of adult lepidopteran

insects attracted the attention of the anatomists. Burgess (1880)

was probably the first worker to give a scientific account of the

digestive system of adult milkweed butterfly, Danais archippus.

Bordas (1920) have studied comparative account of the gross

anatomy and histology of the digestive system of the adults of

several species of Papilionidae, Nymphalidae, Satyridae,

Notodontidae and Saturniidae. Pyle (1940) described the

anatomy and histology of the digestive tract of the adult moth,

Callosomia promenthean in detail. Mortimer (1965) published

a comprehensive account on the anatomy and histology of

the alimentary canal of six species of lepidoptera. The

morphology of the digestive tract of various lepidopterous

species was also studied by many workers, viz. Chauthani

and Callahan (1967), Le Grice (1968), Judy and Gilbert (1970),

Beals and Berberet (1976) and Gongalves (1981). Anatomy

and histology of alimentary canal were studied in Diacrisia

obliqua (Kabir and Ameen, 1986) and Papilio demoleus

(Goyle, 1990).

The butterfly Papilio polytes polytes is a serious and regular

pest of curry leaf, Citrus spp. and other plants of rutaceae

(Haribal, 1992; Gunathigalraj, 1998). The caterpillar is a foliage

feeder prefers blossoms and young nurseries of host plants.

While adult suck the sugary liquid nectar from flowers. The

information available indicates that the studies pertaining to

anatomy and histology of digestive tract in butterflies is scanty.

Therefore, to overcome the lacunae, the anatomy and histology

of digestive tract of adult butterfly Papilio polytes polytes are

described in the present paper.

MATERIALS AND METHODS

Field collected larvae of Papilio polytes polytes were reared

up to the adult stages in rearing cages by providing fresh leaves

of their host plants under laboratory conditions. The adults

were dissected in chilled insect ringer solution under a

stereoscopic binocular microscope for anatomical studies and

observations were made.

The various regions of alimentary canal were fixed in Bouins

fixative for 24 hr. They were washed in water and dehydrated

gradually using ethyl alcohol. After dehydration tissues were

cleared in xylene, infiltrated and embedded in paraffin wax

(54ºC). Tissues were sectioned at 5-7μ. Sections were satined

with Haematoxylene-Eosin (Humason, 1962). Observations

were made and microphotography was done.

RESULTS AND DISCUSSION

Anatomy

The alimentary canal of Papilio polytes polytes adult is typical

lepidopteran type. The length of the alimentary canal is 1.64

times longer than its body. It is about 46 mm long, whereas

length of the whole body is about 28 mm only. The alimentary

canal is long, relatively straight in the region of hindgut (Fig.

1). The two ends of the alimentary canal are attached to the

body wall by means of muscles at the oral and anal region,

elsewhere it is supported by the tracheal branches and fatty

ABSTRACTThe present study provides the description of the anatomy and histology of the alimentary canal of adult Papilio

polytes polytes. The alimentary canal consists of long foregut and hindgut and short midgut. Histologically

foregut and hindgut showed outer muscularis, middle folded epithelium and inner chitinous intima. Midgut

consists of outer muscularis and inner columnar epithelium and peritrophic membrane surrounding gut content.

The epithelium of fore gut and ileum is syncytial and epithelium of colon and rectum is cuboidal. The epithelium

of colon shows characteristic six folds. The crop shows well developed spines internally.

KEY WORDSAnatomy and histology

Alimentary canal

Papilio polytes polytes

Received on :

01.03.2011

Accepted on :

17.06.2011

*Corresponding

author

400

S. M. GAIKWAD et al.,

tissues. Morphologically it is divided into fore gut, mid gut

and hindgut.

Foregut

The foregut is long narrow tube 9.5 - 11 mm in length

contributes about 23.91% part of the alimentary canal and

extends up to the first abdominal segment. It comprises bulb

like sucking pump, narrow diverticulum, lateral diverticulum

or crop and muscular proventriculus. The sucking pump is

composite structure composed of cibarium and pharynx. It is

highly muscular structure situated in the head. The functional

mouth is situated at the base of the proboscis through which

it communicates with the food. The oesophagus is a narrow

tube measures about 10 mm in length. Its first differentiated

region is the balloon like air-filled crop. It is the lateral

diverticulum and it communicates with the esophagus through

a small duct, duct of crop. The crop is insulated with air and

occupies the entire dorsal portion of first three abdominal

segments. Crop measures about 4 mm long and 2 mm in

diameter. The crop is followed by a small, slightly swollen

proventriculus. It is well developed and distinguished from

the rest of the fore gut. Proventriculus is about 1 mm in length.

Midgut

The midgut is short, straight; cylindrical tube extends up to

fourth abdominal segment. It is about 8 mm long and

contributes about 17.39% part of the alimentary canal. It

appears to be segmented externally. The fore gut and mid gut

junction is marked by dilation of the mid gut due to shallow

invagination of the fore gut into mid gut. It is provided with

numerous tracheae and surrounded by fatty tissues.

Hindgut

The hindgut is longest and coiled tube. It is delicate and

measures about 27 mm in length contributing 58.69% of the

entire tract. It is divisible into two regions, the intestine and

rectum. The anterior intestine is divisible into ileum and colon,measures about 24 mm in length. Ileum is short and broad

part while colon is long coiled slender part of the intestine.

The ileum lies in fourth abdominal segment and colon is

restricted in fourth, fifth and sixth abdominal segments. The

rectum is wide pear shaped terminal chamber with anterior

conical and posterior tubular portion, which opens to the

exterior through the anus in tenth abdominal segment. In the

middle of the seventh segment, the intestine passes into rectum

and the junction is marked by presence of rectal diverticulum

measures about 1.5 mm in length.

There are six malpighian tubules arranged in two groups of

three each and open laterally at the junction of midgut and

hindgut.

Histology

Fore gut

Histologically, the foregut is externally surrounded by

muscularis. There are two concentric layers, outer circular

and inner longitudinal muscles. The epithelium is single

layered structure consists of flattened epithelial cells. The cells

have indistinct basement membrane, which usually follows

the longitudinal folds of the epithelium. The epithelium of

foregut is syncytial with more or less granular cytoplasm and

large, oval nuclei. It is lined by intima on the lumen side,

which is thick and shows alternate major and minor folds

along with the epithelial layer (Fig. 2). The intima of

proventriculus is thrown into number of irregular folds and

occupies almost all portion of lumen and proventriculus is

with well developed circular muscle layer (Fig. 3). The muscle

coats of crop are thin, epithelial resolves into minor folds and

lined with intima. In crop, the intima of upper region shows

well developed spines (Fig. 4).

The proventriculus opens into the mid gut through a small

opening guarded by the stomodeal valve. The stomodeal valve

is well developed and extends into the lumen of the midgut

(Fig. 10). It is composed of cuboidal epithelial cells along with

intima of foregut. At the junction of foregut and midgut there is

no any special structure such as proventricular teeth, pads or

spines.

Midgut

Midgut consists of thin muscularis of outer longitudinal and

inner circular muscle layers. The epithelium comprises

transverse and longitudinal folds to provide large absorptive

area. The folds are compact in the anterior region, where as

they are comparatively loose in the posterior part. The epithelial

cells are tall columnar and with large spherical nuclei. The

cytoplasm is granular with globular secretion. The midgut

epithelium shows secretary globules at the free surface and

the secretion is holocrine. The basement membrane is

indistinct. The division of regenerative cells located in the

crypts basally to the columnar epithelial cells. The food is

surrounded by single peritrophic membrane (Fig. 5).

Hindgut

The mid gut opens into the hind gut through an opening

guarded by the pyloric valve (Fig. 11). Histologically, hindgut

consists of outer muscularis, middle epithelium and inner

intima. The epithelium is arranged into several irregular folds

in ileum and characteristic six folds in colon. The epithelium

of ileum is syncytial lined with thick irregular intima. The

epithelium of colon is composed of single layer of cuboidal

cells which are vacuolated at some places. The nuclei of

epithelium are oval or rounded and basement membrane is

prominent. The intima of colon is thin and wrinkled. The

circular and longitudinal muscles of the ileum and colon are

comparatively thicker than the midgut muscularis (Fig. 6 and

7). Rectal glands were found scattered throughout the rectal

epithelium situated below the intima consists of double layer

of cuboidal epithelial cells. The nuclei are large, oval, scattered

in the cytoplasm but cell boundaries are not clear. Posteriorly,

the rectum is tubular and more muscular and it is devoid of

rectal glands. The epithelium of rectal diverticulum is

composed of cuboidal cells with granular cytoplasm and darkly

stained nuclei. The basement membrane limits the epithelium

on its outer side and intima on inner side (Fig. 8).

The alimentary canal of adult Papilio polytes polytes is

differentiated into foregut, midgut and hindgut like that of adult

lepidoptera. These three distinct regions of the alimentary canal

were also observed in Danais archippus (Burgess, 1880),

Serrodes inara (Le Grice, 1968), Hyalophora cerecropia (Judy

and Gilbert, 1970), Elasmopalas lingnosellus (Beals and

Berberet, 1976), Pseudaletia sequax (Gongalves, 1981). The

foregut of Papilio polytes polytes is composed of a sucking

401

pump, oesophagus, crop, proventriculus and stomodeal

valve. Bordas (1920) reported cibaria-pharyngeal sucking

pump, oesophagus and crop in the foregut of several species

of adult Lepidoptera. He noted fine denticulations on the

epithelial folds of foregut. Pyle (1940) recognized buccal cavity

or sucking pump, oesophagus, oesophageal valve and sucking

stomach in the foregut of Callosamia promethean. He reported

that the esophagus is short and narrow with reduced

musculature on its wall. Mortimer (1965) noticed similar

condition in Hepialus. Kabir and Ameen (1986) noted

buccopharyngeal cavity, narrow oesophagus, crop and

oesophageal valve in D. obliqua. They noted that the

musculature is not well developed in foregut. These studies

are more or less similar with the present findings in Papilio

polytes polytes.

The crop is a thin walled balloon like air filled lateral

diverticulum. The epithelial layer is lined with thin spiny intima.

Similar spiny intima was observed in Plusia by Mortimer

(1965). Le Grice (1968) also observed some stout spines on

the floor of the crop in Serrodes inara. The stomodeal valve of

Papilio polytes polytes adult is well developed and is made

up of cuboidal epithelial cells lined with very thin intima.

Mortimer (1965) reported similar valve in Arctia caja. He noted

spiny intima of the valve in Plusia and Hepiatus where as

spines were absent in Papilio polytes polytes. Musculature of

valve of Papilio polytes polytes is well developed agrees the

observation Le Grice (1968) and Mortimer (1965). They noted

well developed musculature in the oesophageal valve of

Serrodes and Plusia respectively. Earlier Bordas (1920)

recorded the columnar cells and replacement cells in the

midgut epithelium of adult lepidoptera. Mortimer (1965)

observed columnar cells, replacement cells and pavement cells

Figure 1: Adult alimentary canal A: oesophagus, B: crop, C: proventriculus, D: mid gut, E: ileum, F: colon, G: Rectum, H: rectal diverticulum,

I: anus. Figure 2: T. S. of oesophagus A: circular muscles, B: longitudinal muscles, C: epithelium, D: intima. Figure 3: T. S. of proventriculus A:

Circular muscles, B: proventricular teeth, C: basement membrane Figure 4: T. S. of crop A: circular muscles, B: epithelium, C: crop spines,

Figure 5: T. S. of midgut: A: longitudinal muscles, B: circular muscles, C: epithelium, D: nidi cells, E: Secretary vesicles, F: gut content, Figure

6 and 7: T. S. of ileim and colon A: circular muscles, B: eithelial cells, C: intima, D: gut content, Figure 8: T. S. of rectum A: epithelium, B:

luminal urine Figure 9: L. S. of rectal diverticulum: A: epithelium, B: luminal urine. Figure 10: L. S. of fore gut-mid gut junction: A:

proventriculus, B: epithelium, C: stomodeal valve, D: peritrophic membrane. Figure 11: L. S. of mid gut-hind gut junction: A: mid gut, B: hind

gut, C: epithelium, D: pyloric valve, E: peritrophic membrane

ALIMENTARY CANAL OF ADULT PAPILIO

402

in the adult midgut epithelium of Micropteryx. A well brush

border along the lumen side of the epithelial have reported by

Le Grice (1968) in Serrodes inara and Kabir and Ameen (1986)

in D. obliqua brush border was not observed but globular

secretion was observed on the free border of the mid gut

epithelium. According to Van Gehuchtan (1890) in

Ptychoptera the granular protrusions on the epithelial cells

are secretion vesicles and when the globules are present, the

cells have no striated border. Present findings strongly support

Van Gehuchetan’s view that the globular secretion at the free

border of mid gut cells of insect under study. In Papilio polytes

polytes the food is surrounded by single continuous

peritrophic membrane. The peritrophic membrane was first

reported by (Aubertot, 1938) in butterfly Pieris brassicae.

Waterhouse (1957) recorded the peritrophic membrane in

adult lepidoptera.

The hindgut of adult Papilio polytes polytes is divisible into

intestine and rectum. The nomenclature used by various

authors, however, differed while describing the hindgut in

different insects. The intestinal epithelium is arranged into

several irregular folds in ileum and characteristic six folds in

colon. It is syncytial in colon and in ileum it is composed of

single layer of cuboidal epithelial cells lined by intima. Goyle

(1990) made similar observations in P. demoleus a closely

related species of Papilio polytes polytes. A large number of

typical rectal glands were recorded by several authors

(Mortimer, 1965; Le Grice, 1968; Beals and Barberet, 1976)

in various species. Mortimer (1965) reported only 3 and 4

rectal glands in Micropteryx and Hepialus respectively. Judy

and Gilbert (1970) found 30-35 rectal pads in Hyalophora

cercropia. In Papilio polytes polytes rectal glands were found

scattered in the rectal wall.

The anatomy and physiology of the digestive system have

significance in the establishment and confirmation of basic

knowledge in the lepidopterous insect. Thus knowledge

would be utilized in planning the strategies for management

of the population of this species and other related species.

REFERENCES

Aubertot, T. M. 1938. Peritrophic membrane: Larvae of Diptera,

Nematocera. Arch. Zool. Exp. Gen. 79: 49-57.

Beals, G. R. and Berberet, R. C. 1976. Anatomy and histology of

selected systems in larval and adult Elasmopalus lingosellus

(Lepidoptera: Pyralidae). Ann. Ent. Soc. Am. 69: 1105-1119.

Bordas, L. 1920. Etude anatomique et Histologique de l’appareil

Digestif des Lipidopteres. Ann. Sci. Nat. (Zool.) 3: 175-250.

Burgess, E. 1880. Contributions to the anatomy of the milkweed butterfly,

Danias archippus. Anniv, Mem Boston Soc. Nat. Hist. 1-16.

Chauthani, A. R. and Callahan, P. S. 1967. Developmental

morphology of the alimentary canal of Heliothes zea (Lepidoptera:

Noctuidae). Ann. Ent. Soc. Am. 60: 1136-1140.

Gongalves, I. S. 1981. Anatomia do tubo digestive de Pseudaletia

sequax Franclemont 1951 (Lepidoptera, Noctuidae). Rev. Bras. Ent.

25: 113-121.

Goyle, S. 1990. Anatomy of the common lemon butterfly, Papilio

demoleus demoleus L. Today and Tomorrow publication, Delhi, p.

151.

Gunathigalraj, K. 1998. Some South Indian Butterflies Nilgiri Wildlife

and Environment Assocaition, Tamil Nadu.

Haribal, M. 1992. The butterflies of Sikkim Himalaya and their Natural

History, Sikkim Nature Conservation Foundation, Gangtok, p. 217.

Humason, G. L. 1962. Animal tissue techniques, Freeman, San

Francisco, London, p. 569.

Judy, K. J. and Gilbert, L. I. 1970. Morphology of the alimentary

canal during the metamorphosis of Hyalophora cecropia (Lepidoptera:

Saturniidae) Ann. Ent. Soc. Am. 62: 1438-1446.

Kabir, A. and Ameen, M. 1986: Anatomy and histology of the

alimentary canal of adult, Diacrisia obliqua Walker (Lepidoptera:

Arctiidae) Bangaladesh J. Zool. 14 (1): 49-57.

Le Grice, D. S. 1968. Some observations on the morphology and

histology of the alimentary canal of the fruit-sucking moth Serrodes

inara Cram. (Lepidoptera: Noctuidae). S. Afr. J. Agric. Sci. 11: 789-796.

Mortimer, T. J. 1965. The alimentary canals of some adult Lepidoptera

and Trichoptera. Trans. R. Ent. Soc. Lond. 117: 67-93.

Pyle, R. W. 1940. The anatomy and histology of the digestive system

of a supposedly non-feeding adult moth, Callosomia promethean

Dur. (Lepidoptera: Saturniidae). Ent. News. 51: 181-185, 211-215.

Van Gehuchtan. 1890. Recherches histologiques sur l’appareil digestif

de la Ptychoptera contaminate. La Cellule. 6: 185-290.

Waterhouse, D. F. 1957. Digestion in insects. Ann. Rev. Entomology.

2: 1-18.

S. M. GAIKWAD et al.,